The objectives of this epidemiological study are to estimate the incidence and prevalence of specific mental disorders both across and within samples of Hispanic and Anglo populations in two catchment areas of Los Angeles county (Venice and East Los Angeles); to study the relationship between psychiatric disorders and the utilization of psychiatric, general health, and other treatment facilities; and to study the relationship of such factors as life stress and sociocultural resources on development and continuation of these disorders and health care utilization patterns. Two sets of personal interviews are conducted one year apart with a randomly selected sample of 3,000 noninstitutionalized adults, divided evenly between the two catchment areas. A telephone followup is made at three, six and nine months intervals to monitor health care utilization patterns. Two sets of personal interviews are conducted with a randomly selected sample of 500 institutionalized adults in the same catchment areas and at the same time periods of the community surveys. The principal diagnostic instrument used in the study is the National Institute of Mental Health Diagnostic Interview Schedule.